RHEOLOGICAL PARAMETERS OF SERUM AND PLASMA OF BLOOD IN PATIENTS OPERATED ON HEART IN THE CONDITIONS OF ARTIFICIAL BLOOD CIRCULATION DURING THE PER- AND INTRAOPERATIVE PERIOD

Abstract

Background. Set the values of surface tension and dilatational viscoelasticity: 1) serum and plasma in patients operated on for the heart under cardiopulmonary bypass, in the peri-and intraoperative periods; 2) blood serum during cardiopulmonary bypass. Materials and methods. In 70 patients with ischemic heart disease, the average age 62,1±0,9, operated on under cardiopulmonary bypass for coronary heart disease and acquired valvular heart disease, the prospective study of surface tension and dilatation viscoelasticity of blood serum and plasma was performed. There were used the methods of drop and bubble form (Tensiometers PAT-1 and РАТ-2P SINTERFACE Technologies, Berlin, Germany).The blood for research was sampled an hour before operation, in the 5th minute of cardiopulmonary bypass, after 12 hours (1-st day) and in 7 days after operation. The rheological active markers (glucose, protein, albumen, urea and creatinine) were choose from routine biochemical parameters to evaluate. Results. On the 1st day after surgery, there was a statistically significant increase in glucose, urea and creatinine levels and a statistically significant decrease in total protein and albumin. Against this background, the nature of the changes in surface tension and viscoelastic modulus indicated a significant increase in serum surfactants. By the 7th day of the postoperative period, positive dynamics of the studied biochemical parameters was noted. Of the rheological indicators, an increase in the module at a frequency of 0.01 Hz can be noted with a simultaneous decrease in the phase angle. This indicates an increase in surface elasticity with a practically constant surface viscosity. Noteworthy are close to zero coefficients of the dependence of dilatational viscosity on the oscillation frequency. At the same time, the group of patients during cardiopulmonary bypass reliably stands out among other groups of patients in terms of the size bviscosity. This indicates a change in the mechanism of formation of dilatational viscosity, probably due to the introduction of large volumes of infusion media into the vascular bed in a short time. Conclusion. Pathological changes in biochemical markers which influence blood viscosity (glucose, protein, albumen, urea and creatinine) were accompanied by significant changes in surface tension and dilatation viscoelasticity of serum and plasma blood. The same time these biochemical markers are not the dominant predictors of the changes in blood rheology and viscosity.

Keywords

• surface tension
• blood rheology
• coronary heart disease
• valvular heart disease.